Reference Article - Expected Purity Range for Barnstead Mega-Pure Glass Stills - December 2024
Details
Megapure glass stills use the distillation method to produce pure water. In the process of distillation water is boiled and undergoes phase changes, going from liquid to vapor and back to liquid. It is the change from liquid to vapor that separates from the water many dissolved impurities, such as ions, organic contaminants with low boiling points <100°C, bacteria, pyrogens, and particulates. The resulting water meets ASTM Type 2 requirements.
Type 2 water is most widely used in general laboratory applications, such as
• Rinsing lab glassware
• Supplying autoclaves and ultrapure water systems
• Preparing and diluting buffers, reagents, and media
Definition
ASTM standards for Type 2 reagent water:
Resistivity at 25°C >1 MΩ.cm
Total organic carbon <50 ppb
Sodium <5 ppb
Chloride <5 ppb
Total silica <3 ppb
Parameters
The expected purity range for the Megapure stills is 1-10 meg ohms.
The purity depends upon pretreatment options and feed water quality, as well as the method of sampling. In-line measurements will indicate higher meg ohm readings versus taking a sample at the end of the system. This is because atmospheric gases and impurities are quickly absorbed by the water as it is exposed to air when collecting the sample and taking the measurement.
Example
The attached PDF details test results from the 3-Liter Megapure model MP-3A still with ACS (Automatic Collection System) storage option.
Megapure Model List
MP-1 models produce 1 Liter/hr
A440266 (6747) 120V system Without Bottle
A440267 (6748) 120V system With Bottle
A7981 (6755) 220-240V system Without Bottle
A7982 (6785) 220-240V system With Bottle
MP-3A models produce 3 Liters/hr
A440696 (6751) 208V system
A440367 (6749) 220-240V system
MP-6A models produce 6Liters/hr
A440518 (6750) 220-240V system
A440697 (6752) 208V system
MP-11A models produce 11 Liters/hr
A440117 (6745) 208V system
A440118 (6746) 240V system
MP-12A models produce 12 Liter/hr
A442012 (6754) 208V system
A442011 (6753) 240V system